Machine-tool fixture



'E. C) LEWIS. MACHINE TooL FIXTURE.

AfPLlATION FILED DEC. 22, 1919.'

Patented im 2s, 1921.

E. C. LEWISl MACHINE TOOL FIXTURE'. A-PPUCATION EILED D'ECLZ'Z. 1919.

.Patented June 28, 1921.

2 swans-SHEET 2.

"Providence, in the county of etres eruit orifice.

EVERETT C. LEW'IS, 0F PROVL'DENCE, RHODE ISLAND.

Application led December 22. 1919.

To all iii/0m :it may concern:

.lie it known that l, Evnnn'rr C. LEWIS, a citizen oi the United States,residing at Providence, State ot Rhode lsland, have invented certain newand useful linprovements in Machine-Tool Fixtures, of which thefollowing is a specilication.

My invention is an improved fixture for holding worlr to be operatedupon in milling machines, grinding machines 01 other niachine-tools.

@ne object of my improvement is to provide a i .ture which will hold theworlr with greater iirniness and rigidity to resist the thrust ot thetool acting against it.

another object of the improvement is to provide for greater facility andconvenience in applying the work to the fixture and for a quicker actionin clamping the jaws of the lixture against the work.

A further object ot the improvement is to render the lixture more easilyand quickly adjustable for pieces of work of varying sizes and shapes.

.another object of the improvement is to provide a iixture of morerugged and stanch striflcturc, capable of resisting strain and wear onits operating parts and having greater durability under hard usage.

Still further objects of the improvement will appear from the followingspecification comprising a detailed description of one embodiinent etthe invention as illustrated by lthc accompanying drawings, in whichlike reference characters designate like parts. ln the drawings:

Figure l is a plan view ot my improved fixture;v

Fig. 2, a longitudinal, sectional elevation ot the device, taken in amedian plane on the line iii-nl.. of Fig. l;

lfig. 3, a detailed View of a portion oi the device in cross-section,taken on the line lil B of Fig. 2;

Fig. it, an elevation of the forward end of he device;

YWig. 5, a side elevation of the device showing a modification in thearri' ngement oi its movable jaw-member which adapts it for liol ngtapered pieces; and

`G, an end view ot' this type et device.

lle'lierring to the dra-wings, 2 designates the main frame or base ofthe iixture which constructed with a relatively broad T- head il at its`forward end, and a narrower Specification of Letters Eatent.

Patented June 28, 151,21.

Serial No. 346.530.

tail-piece l extending rearwardly therefrom. Reaching out from thesidesof the base 2 at the rear of its head 3 are ears 5, see Figs. 1 and 4l,to which are attached tongues 6 for locating the xture on the table T otthe milling-machine or other tool with which it is used. The tongues 6may consist of cylindrical plugs set into counterbores 7 on the underside oi" the ears 5 and secured in place by screws 8. The tongues 6 areadapted to enter a T-slot t on the top of the table T, see lFigs. l andLl, to hold the ixture square therewith. The tongues may also beinserted in other counterbores 9 at the forward and rearward ends of thebase 2, see Fig. 2, to adapt the fixture to be set parallel with theslot t in the table T. it the center of the base 2 is a fastening-bolt11 having a head 12 at its lower end adapted to underlie the sides ofthe T-slot t in the table T, as shown in Figs. 1 and 2. The bolt l1carries a nut 13 at its upper end arranged in a cut-out recess 1iin thebase 2, so that `it may be turned by a wrench to draw the head 12 of thebolt against the overhanging sides of the slot t to clamp the ixturedown against the table T.

The top of the base 2 is formed with a rectangular slot 15 extendingthroughout its length, longitudinally of the tail-piece 4l. Fitted toslide in the slot 15 is a square bar 16 which serves as a. movablesupport for the outer jawcarrying member 17 of the fixture. A cap i8,conforming to outline of the base 2, .is litted its top across the slot15 to hold lthe bar 16 in place therein, the cap being secured to thebase by screws i9 and dowel-pins 20. i-ibutting the torward end ot thecap 18 is the fixed jaw 21 which is secured thereto by screws 22reaching through from the rear. rllhe movable jaw support 17, beforementioned, is iitted to a stud 23 projecting from the forward end of thesliding bar 16 and is formed with lugs or ribs 24 abutting the sides ofthe square end of the bar to prevent it from turning thereon. rPhejaw-support 17 is held against a shoulder 25 on the bar 16 by means o anut 27 screwed onto the tl'ireaded end 28 of the stud 23 against washer29. @n the jaw-support t7 is the movable aw 30 oit' hardened steel,similar to the lined jaw 21, and held in place by the screws 31.

The movable jaw is adapted to be drawn toward the xed jaw 21,'to clampthe work W therebetween, by the sliding -nut 58 formed thereon.

movement of the bar 16. rllhe bar 16 is slid rearwardly through the slot15 of the base 2 under the action of a cam 35 operated from a handledlever 36. The cani 35 is rotatable on a stud 37 with its curved edge 38bearing against a hardened thrust-plate 39. The plate 39 is set in aslot 40 at the rear of the cap 18, which, as will be noted by referenceto Figs. 1 and 2, does not extend clear to the end of the tail-piece 4of the base 2. rlhe plate 39 is held in place by a suitable means, suchas the pins 41, and serves as a wearresisting element to taire thethrust of the cam 35. The handle or lever 36 has a hub 42 rotatablymounted on the stud 37 and held in place by the countersunlr head of ascrew 43 screwed down into the stud. Biveted through the lever 36 is apin 44 which projects downwardly to adapt it to enter any one of aseries of holes 45 spaced around the cam 35. By removing the screw 43the lever 36 may be lifted and turned in relation to the cam 35, its pin44 being then set in any one of the holes 45 to provide for the mostconvenient position of the handle in accordance with the location of thefixture on the tool.

Referring particularly to Fig. 2, the stud 37 is held in a rectangularslide or block 56 fitted to the slot 15 in the base 2 in which the bar16 slides. Reaching forward from the slide 56 is a threaded rod or bolt51 which is screwed into the aXial, threaded bore 52 of a stud 53. rThestud 53 is fitted to a longitudinal bore 54 in the sliding bar 16 and isprovided with a head 55 abutting the rearward end thereof. The forwardend 56 of the stud 53 is reduced in diameter and projects through thestud 23 at the front end of the bar 16. Its protruding end isscrewthreaded at 57 and terminates in a square Screwed onto the threads57 is anut 59 acting against the washer 60 which abuts the end of thestud 23 on the bar 16. The nut 59 coperates with the head 55 on the stud53 toi hold the latter longitudinally of the bar 16, while allowing itto turn therein. By turning the stud 53 through the means of a wrenchapplied to its squared end 53 the movable 30 may be adjusted in relationto the fixed jaw 21 in the manner and for the purpose as hereinaftermore fully explained.

0n the top of the black 50 is a cover-plate 61 which is held in place bythe cam 35 and slides in the slot 15 in the base 2. 1t will be observedfrom Figs. 3 and 5 that the sides ofthe slot 15 extend above the top ofthe bar 16 along the tail-piece 4, the cap 18 being cut away at 62 onits under side to provide a space for the plate 61 as shown in Fig. 2.The plate 61 slides in under the cap 18 and covers the slot 15 at therear of the cap to prevent dirt or chips from working down into theslot.

The stud 37 is held in the bloclr 50 by means of a set-screw 63, seeFig. 2, screwed in from the rear of the block with its end engaging aslot 64 on the side of the stud. The thread-ed hole 65 for the set-screw63 also receives the end of a bolt 66 which fastens a guide-member 67 tothe rear face of the block. The member 67 consists of a vertical plate68 provided with a cylindrical sleeve 69 projecting forwardly from itslower end. rilhe sleeve 69 enters a horizontal bore 76 in the base 2 andslides therein under the movement of the block 50; thereby acting as aguide and brace for the block to prevent it from raising up out of theslot 15 in the base. The sleeve 69 also serves as a housing for a coiledspring 71 which acts to draw the bloclr or slide 50 forward in thefixture to force its jaws apart and maintain the cam 35 bearing againstits thrust-plate 39. One end of the spring 71 is anchored to a pin 72extending across the bore of the sleeve 69; while its opposite end isfastened to a cross-pin 73 at the end of the bore 70.

ln the modified form of the device illustrated in Figs. 5 and 6 lprovide a rockable support 75 for the movable `iaw 30 which is pivotedto rock` on a horizontal axis on the sliding bar 16. As shown moreparticularly in Fig. 6, the support 75 is formed with lateral bearings76 abutting the sides of the bar 16 and pivoted thereto by screws 77. The screws 77 are screwed through the sides of the support 75 andprovided with reduced extensions 78 engaging bores 79 in the op- `iositesides of the bar 16. rlhe support 75 carries the jaw 30 secured at itstop by the screws 31, and below its bearings 76 is a triangularextension 8O carrying an adjustingscrew 61 at the bottom with acheck-nut 82 on its outer end. rEhe screw 81 is rounded off on its innerend and bears against a hardened block 83 set into the front of the base2. By releasing the check-nut 82 the screw 81 may be 'adjusted throughits bearing in the support 75 to rock the latter on its pivots 7 6,whereby to vary the angularity of the working face of the jaw 36 toadapt it to the taper of an angular piece W held .in the fixture. heconstruction and arrangement of the parts of my improved device havingnow been described in detail, its method of operation will next beexplained.

My improved fixture is attached to the table 'll of the milling machineor other machine-tool by setting the tongues 6 in the appropriatecounierbores 7 or 9 and engaging them in the T-slot t in accordance withthe position in which the device is to set. rllhe holding screw 11 atthe center of the base 2 is also slid into the slot t, `with its head 12underlying the sides thereof, and when its nut 13 is tightened it willclamp the fixture firmly in place on the table T. T he device is mostgenerally used where it is required to machine or finish pieces ofuniform dimensions in quantity lots, although it is equally well adaptedfor individual work, as in toolmalring. lhere the work is uniform onlyone adjustment of the jaws of the fixture is necessary and this isaccomplished in the following manner: The handle or lever 36 is swungaround to turn the cam 35 into the position illustrated by thedash-lines in Fig. 1 with its straight side against the thrust-plate 39.This action allows the spring 71, acting through the guide-member 67, toslide the block 50 forward in the slot 15, and the bolt 51 on the blockpushes the slide-bar 16 forward to move theA jaw 30 away from the fixedjaw 2l. The piece WT to be operated upon is next placed in positionbetween the jaws, and the outer janY 30 adjusted on the stud 23 of' thebar 16 to leave a slight space between it and the side of the piece. Thejaw 30 is adjusted in relation to the fixed jaw 21 by turning the stud53 with a wrench applied to its squared end 58, whereby to eitherslierten or lengthen the telescoping connection 51-56 between the slide50 and bar 16. Now when the operating handle 36 is turned back in thedirection indicated by the arrow 0J, Fig. l, the rounded face 38 o'f thecam will be brought against the thrust-plate 39 to cause the slide orblock 50 and its connected bar 16 to be withdrawn through the base 2,whereby to draw the movable, jaw 30 toward the fixed jaw 21 to clamp thework WV therebetween. This action causes the jaws to bind iirmly againstthe sides of the piece lll, thus holding it with a firm grip until thehandle is thrown back again to release the wedging action of the cam. Itwill be noted from Fig. l that the curved face 38 of the cam 35 isformed eccentric to the axis of the stud 37 on which the cam turns sothat a more extended movement oit the jaw 3() may be ettected by turningthe handle 56 beyond the point shown in the drawing. lThis provides fora considerable range of action of the jaws to accommodate pieces ofdifferent thickness, and where a greater movement is required the outerjaw 30 may be further adjusted on the slide-bar 16.

ln the modified form of device shown in Figs. 5 and 6 the outer jaw 3()may be adjusted at an inclination to the vertical to accommodateangular-sided pieces and, when necessary, the working tace of the jaw 21may be beveled or inclined to accommodate dilierent shapes in the work.

My improved device provides for a quick action of the jaws both ingripping and releasing the work, and their clamping effect isparticularly powerful and secure. it is to be observed that the work Wis held against the iixed jaw of the device in such manner that thethrust of the tool on the piece will be taken on the solid base oi thefixture, whereby to provide greater rigidity and to prevent chatteringor vibration of' the tool on the work. it is also to be noted that theoperating handle or lever 36 may be adjusted on the cam 35 through anangle of one hundred and eighty degrees so that it may be set inwhatever relation is most convenient for the operator in accordance withthe different positions in which the fixture is set on the machine.

Particular attention is called to the stanchness of the device asprovided by the structure of its base 2 and the arrangement of theoperating parts within the base. it

will also be noted that this self-contained feature ot the mechanismprotects the working parts from dirt and chips, while making forimprovement in the general appearance and neatness of the device. Myimproved fixture is lighter and more compact than the usual devicesemployed for like purposes, yet is particularly stanch and rugged andproof against wear or deterioration under hard usage.

Various modifications might be made in the design and structure of. thedevice without departing from the spirit or scope of the invention;therefore, without limiting myself to the exact embodiment herein shownand described, what I claim and desire to secure by Letters iBatent is:

1. ln a fixture for machine-tools, the combination with a base, of afixed jaw on said base, a movable jaw, a support for the movable awslidable on the base, automaticallyoperated means for sliding thesupport to open the jaws7 a cam for sliding the support to close the jaws7 and a variable connection between the cam and support for adjustingthe operative relation between the movable jaw and fixed jaw.

2.' ln a fixture for machine-tools, the combination with a base, of afixed jaw on said base, a movable jaw arranged opposite the fixed jaw,resilient means for sliding the movable jaw away from the fixed jaw,means to slide the movable jaw toward the fixed jaw, a cam for operatingsaid means, and means for adjusting the position of the sliding means tovary the operative relation between the movable aw and fixed jaw.

3. .in a fixture for machine-tools, the combination with a base, offixed jaw on said base, a member slidable on the base, a movable awcarried by said member, means connected to slide the jaw-carryingmember, means for manually operating the slidingmeans to close the jaws,means for automatically operating the sliding` means to open the j aws,and means for adjusting the connection between said sliding-means andthe jaw-carrying member to vary the width of the opening between thejaws.

4. In a machine-tool fixture, the combination with a base, of a lixedjaw on said base,

a movable jaw, a slidable support tor the movable jaw, a spring forsliding the support to move the movable jaw away from the fixed jaw, arotatable cam for sliding said support to move the movable jawl towardthe `iixed jaw, a lever for operating the cam, and means for connectingthe lever with the cam in diiierent positions of angular adjustmentwhereby to provide Jfor the most convenient position of operation oi thelever.

5. In a machine-tool fixture, the combination with a base, of a fixedjaw on said base, a movable jaw, a slidable support for the movable jaw,a rotatable cam for sliding said support, said cam provided with aser-ies of holes arranged circumierentially of its axis, a lever pivotedon the axis of the cam, and a pin carried by the lever and adapted 'forengagement with the holes in the cam to connect the lever therewithwhile providing for its adjustment in angular relation thereto.

G. In a machine-tool lixture, the combination with a base, oi a lixedjaw on said base, a support slidable on the base, a movable jaw carriedby said support, a slide for sliding the support, manually-operablemeans forsliding the slide, and means extending through the base toconnect the slide with the support, said connecting-means beinglongitudinally-adjustable to vary the operative relation between themovable jaw and fixed jaw.

7. In a machine-tool fixture, the combination with a base, oi a fixedjaw on said base, a support slidable on the base, a movable jaw carriedby said support, a slide for sliding the support, manually-operablemeans for sliding the slide, a screw-threaded telescopie connectionextending through thebase between the slide and support, and means foradjusting said connection longitudinally to vary the operative relationbetween the movable jaw and {ixed j aw.y

8. ln a machine-tool fixture, the combination with a base, of a fixedjaw on said base, a movable jaw, a slidable support tor the movable jaw,a slide for sliding the support, manually-operable means for sliding theslide, a screw-threaded telescopic connection on the slide extendingthrough the base, and adjustable means on the support engaging thethreads of the connection to vary the longitudinal relation between theslide and support to regula-te the operative relation between themovable jaw and fixed jaw.

9. ln a machine-tool fixture, the combination with a base, of a fixedjaw on said base, a movable jaw, a slidable support for the "movablejaw, a slide for sliding the support, manually-operable means Jforsliding the slide, a screw projecting from the slide, and a rotatablestud held longitudinally of the support and provided with aninternallythreaded bore engaging the end oi the screw, said stud havingmeans at its end whereby it may be turned to adjust the longitudinalrelation between the slide and support to regulate the operativerelation of the jaws.

l0. in machine-tool ixture, the combination with a base, oi a jaw onsaid base, a bar slidable in the base, a movable jaw carried by saidbar, a slide for sliding the bar, manually-operable means for slidingthe slide, a stud rotatable in the support and projecting therefrom witha nut at its end, and a screw on the slide engaging a threaded bore inthe stud.

1l. in a machine-tool fixture, the combination with a base, of a iixedjaw on said base, a bar slidable in the base, a movable jaw at the endoi' the bar, a slide slidable on the base, a cam rotatable on the slideto act against the base, and an adjustable screwthreaded telescopicconnection between the slide and bar for varying the operative relationbetween the jaws.

l2. in a machine-tool fixture, the Combination with a base, ot a barslidable in a slot in the base, a cap for holding the bar in its slot inthe base, a iixed jaw on said cap, a movable jaw on the end of the bar,a slide slidable in the slot in the base, an adjustable telescopicconnection between the slide and the bar, and a cam rotatable on theslide to adapt it to act against the cap to slide the bar to open andclose the jaws.

13. in a machine-tool fixture, the combination with a base, of a barslidable in a slot in the base, a cap 'for holding the bar in the slot,a fixed aw on the cap, a movable aw on the bar, a slide slidable in theslot in the base, a longitudinally-adjustable connection between theslide and bar, a cam ior sliding the slide to move the bar to draw themovable jaw toward the fixed jaw, anda spring acting on the slide tomove the bar to open the jaws. Y

In a machine-tool fixture, the combination with a base, oi a rectangularbar slidable in a slot in the base, a lixed jaw on the base, a movablejaw, a support for the movable jaw fitted to the end ot the slidablebar, a nut 'for securing the support on the bar, an elongated studextending through a bore in the bar and projecting forwardly tnerefromwith nut at its end, means tor holding the stud longitudinally oi thebar while allowing it to turn therein, a slide, a screw on the slidethreaded into the stud in the bar, and a cam for sliding` the slide tomove the bar to open and close the jaws.

l5. ln a machine-tool fixture, the combination with a base, ot a bar slidable in a slot in the base, a cap for holding the bar in the slot, aiixed jaw on the cap, a movable jaw on the bar, a slide slidable in theslot in the base, a Cam ."'of sliding the Slide, alongitudinally-adjustable connection between the slide and bar., and aGuide projecting rlownwaidly iom the slide and slidable iii a bore inthe base to Steady the movement of the slide.

1G. ln a maoliiiie-tool ixtule7 the eombination with a base, of a bai'slidable in a Slot in ltbe base, a Cap for holding the bai' in the slot,a .fixed jaw on the cap, a movable jaw on tbe bar, a slide slidable inthe slot in the base1 a Cam for sliding; the slide, a longitudinally-adjustable connection between tlie Slide and bar, a guide on theslideliaviugahollow stud slidable in a bote in the base, and a s iiiiighoused in Said Stud and bote and aetinge; on tlie ,guide to slide theslide against the action o't the cam.

17, lin machine-tool Fixture, the combination with a base, of a fixedjaw on the base, a support Slidable on the base, a movable jaw carriedby said support, means extending between the movable jaw and the basefor adjusting` tbe jaw in angular position on the support, a slide forsliding the support to move the movable jaw toward and away from thefixed j aw, a longitudinally-adjustable connection between the slide andsuppo't, and a Cam for operating the slide to open and close the jaws.

18. In a machine-tool lixture, the Combination with a base, of a fixedjaw on the base, a Support slidable on the base, a movable jaw pivotallymounted on the support to adapt it to rock in relation to the fixed jaw,an adjusting-screw oaried'by the jaw and adapted to engage the base forrocking the jaw on its support, and manually-operable means for slidingthe support to move the movable jaw toward and away from the fixed Jaw.

ln testimony whereof l aliix my signature.

EVERETT U. LEWIS,

